Disturbing video footage from Nigeria shows the country’s military apparently abusing civilians during their fight against militant group Boko Haram.

The footage appears to show Nigerian soldiers slitting the throats of Boko Haram suspects and dumping their bodies in a mass grave.

Human rights group Amnesty International is accusing the Nigerian military of killing more than six hundred released prisoners.

Makmid Kamara, an Amnesty International Nigeria researcher said: “The people in the video are people who are believed to be Nigerian military officers as well as member of the civilian JTF. We are calling on the Nigerian authorities to investigate this immediately and to ensure that those who are responsible are brought to justice in a fair trial.”

Amnesty alleges the violence against civilians constitutes war crimes.

Makmid continued: “The situation in north-eastern Nigeria in relation to the activities of Boko Haram and the Nigerian military response to the violence of Boko Haram has been escalating. It has gone beyond a situation where the ordinary people in that part of the country can feel safe.”

Boko Haram came to international attention when they kidnapped more than 200 schoolgirls, who still remain captive.

Amnesty’s allegations back up earlier reports by The Associated Press that human rights abuses are being committed by all sides in Nigeria.

Nigerian authorities have rejected past accusations, saying its military follows international best practice in its fight against the group.